Low health literacy is associated with poorer health
outcomes and poorer use of health care services, according to recently
published data in the Annals of Internal Medicine.
Approximately 80 million Americans have limited health
literacy, or the ability to understand labels, interpret numbers and
measurements and talk to doctors. Commissioned by the Agency for Healthcare
Research and Quality, researchers at RTI International-University of North
Carolina Evidence-Based Center updated a 2004 systematic literature review
determining whether low health literacy is related to poorer use of health
care, outcomes, costs, and disparities in health among persons of all ages.
Two reviewers independently selected studies that
compared outcomes by differences in directly measured health literacy or
numeracy levels. One reviewer abstracted article information into evidence
tables; a second reviewer checked information for accuracy. Two reviewers
independently rated study quality by using predefined criteria, and the
investigative team jointly graded the overall strength of evidence.
The update identified 96 relevant good- or fair-quality
studies in 111 articles: 98 articles on health literacy, 22 on numeracy and
nine on both. Low health literacy was consistently associated with more
hospitalizations; greater use of emergency care; lower receipt of mammography
screening and influenza vaccine; poorer ability to demonstrate taking
medications appropriately; poorer ability to interpret labels and health
messages and, among elderly persons, poorer overall health status and higher
Poor health literacy partially explains racial
disparities in some outcomes. The reviewers could not reach firm conclusions
about the relationship between numeracy and health outcomes because of few
studies or inconsistent results among studies.
For more information:
- Berkman ND, et al. Low health literacy and health outcomes: An
updated systematic review. Ann Intern Med. 2011;155:129-130.